Rigid-Flexible PCB Chip Mounting via Localized Rigid Portion
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Solution Overview
Problem
Existing chip package structures face complexity and increased manufacturing costs due to the need to mount chips on rigid substrates before transferring them to printed circuit boards, or face difficulties in mounting chips directly on flexible PCBs.
Innovation Solution
A method for manufacturing a rigid-flexible PCB structure, where a flexible PCB is enhanced with semi-curable glue pieces and copper foil layers to create a rigid portion, allowing for easier chip mounting directly on the rigid portion using wire bonding or flip chip packaging.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a chip is mounted on a rigid substrate first, then the rigid substrate with the chip can be mounted on the PCB, then the chip mounting process is completed, but the process becomes complex and manufacturing cost increases
Solution Approach 1:
The patent combines the rigid substrate and flexible PCB into a single integrated structure. The rigid substrate is positioned on one side of the flexible PCB and bonded together, eliminating the need for separate mounting steps. This merging of components directly reduces process complexity while maintaining reliable chip mounting capability.
Solution Approach 2:
The patent segments the PCB structure into rigid and flexible portions, allowing each to serve its specific function optimally. The rigid portion provides stable chip mounting, while the flexible portion maintains flexibility benefits. This segmentation resolves the contradiction by allowing direct chip mounting on the rigid portion without requiring separate rigid substrate assembly steps.
2Ease of manufacture
If a chip is directly mounted on a flexible PCB, then the manufacturing steps are reduced, but it becomes difficult to mount the chip on the PCB
Solution Approach 1:
The patent applies local quality by creating a rigid portion specifically at the chip mounting area of the flexible PCB. The rigid substrate is positioned and bonded to form a rigid portion that provides stable chip mounting, while the rest of the PCB remains flexible. This localized rigidity makes chip mounting easy while preserving the overall flexibility benefits.
3Stability of the object's composition
If a rigid substrate is used for chip mounting, then chip mounting stability is improved, but the overall PCB flexibility is lost
Solution Approach 1:
The patent segments the PCB into rigid and flexible portions, with the rigid substrate forming a rigid portion on one side of the flexible PCB. This segmentation allows the rigid portion to provide stable chip mounting while the flexible portion maintains PCB flexibility, resolving the contradiction between stability and adaptability.
Solution Approach 2:
The patent implements local quality by making only the chip mounting area rigid through the rigid substrate, while the rest of the PCB remains flexible. This localized approach ensures chip mounting stability where needed while preserving overall PCB flexibility for routing and bending in other areas.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This approach simplifies the chip mounting process, reduces manufacturing steps, and lowers costs by enabling direct chip attachment to the rigid portion of the rigid-flexible PCB, while maintaining the flexibility benefits of a flexible PCB.
Implementation Method 1
The first and second glue pieces 120 and 140 are solidified after being pressed. The solidified first and second glue pieces 120 and 140 and the fixing portion 115 form a rigid portion of the rigid-flexible PCB 100.
Data Source
AI summary
A package structure includes a flexible-rigid PCB and a chip. The flexible PCB includes a flexible PCB, a glue piece and an outer trace layer. The flexible PCB includes two bending portions and a fixing portion connected between the two bending portions, and includes an insulating layer and an inner trace layer formed on the insulating layer. The glue piece is adhered to the fixing portion. The outer trace layer is adhered to the glue piece and includes conductive pads. The fixing portion, the glue piece and the outer trace layer form a rigid portion, the bending portions form flexible portions. The chip is packaged on the rigid portion and includes electrode pads electrically connected to the conductive pads.